/Engine/Plugins/Animation/RigLogic/Source/RigLogicLib/Public/terse/types/Blob.h
Blobis a wrapper type around a byte-array essentially, and is used to serialize binary blobs, whose size is predefined by another entity (e.g. anArchiveSizeobject). During serialization, the amount of bytes either written to or read from the stream will be controlled by the user (by setting the size on the blob type through the setSize member function). For text-based serializers, binary blobs are Base64 encoded/decoded.
template<typename T, typename TAllocator> class Blob